ExoMol molecular line lists – XXIII. Spectra of PO and PS

Abstract

Comprehensive line lists for phosphorus monoxide ( 31 P 16 O) and phosphorus monosulphide ( 31 P 32 S) in their X 2 Π electronic ground state are presented. The line lists are based on new ab initio potential energy (PEC), spin-orbit (SOC) and dipole moment (DMC) curves computed using the MRCI+Q−r method with aug-cc-pwCV5Z and aug-cc-pV5Z basis sets. The nuclear motion equations (i.e. the rovibronic Schrödinger equations for each molecule) are solved using the program Duo. The PECs and SOCs are refined in least-squares fits to available experimental data. Partition functions, Q(T ), are computed up to T = 5000 K, the range of validity of the line lists. These line lists are the most comprehensive available for either molecule. The characteristically sharp peak of the Q-branches from the spin-orbit split components give useful diagnostics for both PO and PS in spectra at infrared wavelengths. These line lists should prove useful for analysing observations and setting up models of environments such as brown dwarfs, low-mass stars, O-rich circumstellar regions and potentially for exoplanetary retrievals. Since PS is yet to be detected in space, the role of the two lowest excited electronic states (a 4 Π and B 2 Π) are also considered. An approximate line list for the PS X -B electronic transition, which predicts a number of sharp vibrational bands in the near ultraviolet, is also presented. The line lists are available from the CDS

The ExoMol Atlas of Molecular Opacities

“…Figure 9. Cross sections generated from ExoMol line lists for sodium chloride [54], potassium chloride [54], phosphorous monoxide [71], carbon monosulfide [61] and phosphorous nitride [55]. Figure 10 shows cross sections for the important species CO plus CN, CP and CaO.…”

“…Figure 11. Cross sections generated from ExoMol line lists for nitric oxide [9] and phosphorous monosulfide [71]. Figure 12 shows cross sections for LiH, ScH, FeH and NH.…”

ExoMol line lists XXXI: spectroscopy of lowest eights electronic states of C2

“…see also Prajapat et al (2017) and Yurchenko et al (2018a). Here r ref is a reference position equal to r e by default and β 2 and β 4 are damping factors.…”

EXOCROSS: a general program for generating spectra from molecular line lists

“…This is especially important when working with line lists containing tens of billions lines. At different stages of development ExoCross was used to generate spectra by Underwood et al (2016b,a); McKemmish et al (2016); Wong et al (2017); ; Yurchenko et al (2017a); Owens et al (2017); Prajapat et al (2017); Yurchenko et al (2018) and Rutkowski et al (2018).…”